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1.
P. Apicella Eric Legallet Elisabeth Trouche 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1997,116(3):456-466
In the primate striatum, the tonically discharging neurons respond to conditioned stimuli associated with reward. We investigated
whether these neurons respond to the reward itself and how changes in the behavioral context in which the reward is delivered
might influence their responsiveness. A total of 286 neurons in the caudate nucleus and putamen were studied in two awake
macaque monkeys while liquid reward was delivered in three behavioral situations: (1) an instrumental task, in which reward
was delivered upon execution of a visually triggered arm movement; (2) a classically conditioned task, in which reward was
delivered 1 s after a visual signal; (3) a free reward situation, in which reward was delivered at irregular time intervals
outside of any conditioning task. The monkeys′ uncertainty about the time at which reward will be delivered was assessed by
monitoring their mouth movements. A larger proportion of neurons responsive to reward was observed in the free reward situation
(86%) than in the classically conditioned (57%) and instrumental tasks (37%). Among the neurons tested in all situations (n = 78), 24% responded to reward regardless of the situation and 65% in only one or two situations. Responses selective for
one particular situation occurred exclusively in the free reward situation. When the reward was delivered immediately after
the visual signal in the classically conditioned task, most of the neurons reduced or completely lost their responses to reward,
and other neurons remained responsive. Conversely, neuronal responses invariably persisted when reward was delivered later
than 1 s after the visual signal. This is the first report that tonic striatal neurons might display responses directly to
primary rewards. The neuronal responses were strongly influenced by the behavioral context in which the animals received the
reward. An important factor appears to be the timing of reward. These neurons might therefore contribute to a general aspect
of behavioral reactivity of the subject to relevant stimuli.
Received: 16 September 1996 / Accepted: 1 April 1997 相似文献
2.
Influence of acetylcholine on neuronal activity of monkey amygdala during bar press feeding behavior
L zl L n rd Yutaka Oomura Yasuhiko Nakano Shuji Aou Hitoo Nishino 《Brain research》1989,500(1-2):359-368
Single neuron activity in the monkey amygdala was investigated during cue signalled conditioned bar press feeding behavior and the effects of electrophoretically applied acetylcholine (ACh) and atropine were analyzed. ACh increased the firing rate of one third of the neurons tested; these excitatory responses were inhibited by the muscarinic receptor antagonist atropine. No characteristic location of ACh-sensitive neurons was found, cells were diffusely distributed throughout the amygdala. Activity of ACh-sensitive neurons did not correlate with any particular event during the bar press feeding task. However, continuous application of ACh at low current intensity during the task significantly enhanced the task-related excitatory firing patterns, or markedly attenuated the inhibitory responses. Continuous application of atropine elicited or enhanced inhibitory response patterns. These results suggest that the cholinergic system of the monkey amygdala facilitates neuronal excitation but attenuates inhibition related to various phases of feeding behavior, such as to cue recognition, food aquisition and rewarding process. 相似文献
3.
An electron microscopic study of local anesthetic-induced skeletal muscle fiber degeneration and regeneration in the monkey 总被引:1,自引:0,他引:1
An electron microscopic study was done on abductor pollicis brevis muscles of 18 Rhesus monkeys after intramuscular injections of 0.75% bupivacaine, 2% mepivacaine, or 2% lidocaine + epinephrine. The muscles were examined for from 2 h to 28 days. Severe muscle fiber damage, consisting of breakdown of sarcolemma and myofibrils, was seen as early as 2 h. Phagocyte mediated fragmentation of the degenerating muscle fibers was at its peak during the third and fourth days. Myoblasts were abundant during the fourth day. Early myotubes appeared on the fifth and sixth days, and they matured during the second week. Satellite cells appeared alongside mature myotubes. Overall, the local anesthetic-induced breakdown and regeneration of skeletal muscle fibers in the monkey followed a course quite similar to that seen in the rat. 相似文献
4.
本实验表明,猕猴高脂造型22—28个月,其大脑中动脉(Middle Cerebral Artery:MCA)内皮发生水肿、细胞间隙变宽,局部破裂等改变,中膜平滑肌细胞增生、迁移。老年高脂组病损程度较重,且中央支也表现出类似改变。结果提示,高血脂可以引起脑动脉硬化性改变,且病损程度与年龄因素密切相关。 相似文献
5.
Single neuron activity was recorded in the monkey anterior putamen to compare visuomotor-related responses during operant bar-press behavior with visual discrimination of objects. Of 615 neurons recorded 9.8% (
) responded to the presentation of food during forced delay of access to the bar. Of these 60 neurons, 38 were also tested with nonfood, and 19 of these responded to the nonfood objects regardless of the following movement. The amplitude of the visual-related responses of some differential neurons was graded for different objects to reflect the relative degree of preference for the food presented. However, these responses disappeared in reaction time tasks in which the bar could be accessed for pressing immediately upon presentation of an object. The visual response latency of differential neurons ranged from 50 to 700 ms (mean ± SD, 386 ±211 ms), which was longer than that of the nondifferential responses (207 ± 204 ms). These results suggest that anterior putamen neurons might participate in estimation of visual information that could be related to forecasting movement. 相似文献
6.
T. D. Aumann J. A. Rawson M. K. Horne 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1998,119(2):179-190
Extracellular single-unit recordings were made from cerebellar dentate neurones in two conscious monkeys trained to perform
wrist flexion and extension movement tasks that produced a range of static joint positions and dynamic velocities. The experiment
was designed to establish whether there is a relationship between the discharge of dentate neurones and movement kinematics.
The discharge patterns of 58 “wrist-related” neurones were correlated with joint position, duration of unidirectional movement
(referred to as duration of velocity) and amplitude of velocity (peak velocity). Significant (P<0.05) correlations were found between the level of tonic discharge and static joint position in 21 of 58 (36%) neurones.
Correlations between phasic discharge and at least one of the velocity variables were found in 17 of 43 (40%) neurones [7
of 43 (16%) showed a correlation between the duration of phasic excitation associated with movement and duration of velocity,
5 of 43 (12%) between the peak rate of phasic excitation and peak velocity and 10 of 43 (23%) between the number of discharges
in the period of phasic excitation and peak velocity]. We conclude (for reasons outlined in the Discussion) that there is
not a strong relationship between neuronal discharge and kinematic parameters of wrist movement in the dentate nucleus.
Received: 21 October 1996 / Accepted: 14 August 1997 相似文献
7.
H. Nishino Y. Oomura Z. Kardi S. Aou L. Lnrd Y. Kai A. Fukuda C. Ito B.I. Min C.P. Salamant 《Brain research bulletin》1988,20(6):839-845
Single neuron activities in the lateral hypothalamic area (LHA) were recorded during bar press feeding task in the monkey. First registered neurons were sorted into 2 groups, glucose-sensitive (GS) and glucose-insensitive (GIS) neurons, depending on their glucose sensitivity. Then firing variations to feeding, electrophoretically applied catecholamines and opiate, and to odor and taste stimuli were investigated. GS neurons responded to dopamine, noradrenaline and morphine more often than GIS neurons. In feeding task GS neurons responded during bar press (BP) and reward (RW) periods with long-lasting inhibition of firing and at cue tone (CT) with transient inhibition, while GIS neurons responded during BP and RW periods mainly with excitation and at cue light (CL) with excitation. A majority of GS neurons responded to both odor and taste stimuli more often than GIS neurons. Data suggest that these two kinds of neurons in the LHA may be involved in different functional aspects of feeding: GS neurons, mainly in internal information processing and reward mechanism, and GIS neurons, in external information processing and motor aspects. 相似文献
8.
The distribution patterns of choline acetyltransferase (CAT), as a marker for cholinergic neurons, and Calbindin-D28k (CaBP) immunoreactivities in the forebrain basal ganglia of the Japanese monkeyMacaca fuscata were compared. Similar distribution patterns of CAT and CaBP immunoreactivities were found in the medial septal nucleus (MS) and the nucleus of the diagonal band of Broca (DBB). Double-labeling fluorescence immunocytochemistry revealed that most, but not all, cholinergic neurons were CaBP-immunoreactive in the MS and DBB. The results suggest that CaBP may play a role in the septohippocampal cholinergic neuron system of the monkey. 相似文献
9.
Yamamoto T. Hassler R. Huber C. Wagner A. Sasaki K. 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1983,51(1):77-87
Summary Thalamic projections of the pallidum and the deep cerebellar nuclei were studied by unitary recordings as well as field potential analysis in the thalamus of squirrel monkeys (Saimiri sciureus) under sodium pentobarbital anesthesia.Stimulation of the pallidum produced a positive field potential preceded by incoming afferent fiber volleys in the thalamus. Spontaneous discharges of thalamic neurons were suppressed during this positive potential, and intracellular recordings from the thalamic neurons revealed that the time course of this field potential corresponded to that of the hyperpolarizing potential. The hyperpolarization was presumed to be a monosynaptic inhibitory postsynaptic potential by the short synaptic delay (about 0.5–0.7 ms) and responsiveness to high frequency stimulation (over 150 Hz). The positive field potential on stimulation of the external pallidal segment was distributed in L.po (VA) and the reticular thalamic nucleus around L.po, whereas that on stimulation of the internal segment was in V.o.a (the anterior basal part of VL) and in Z.o (upper part of VL). The projection of the external segment appeared to be less dense than that of the internal segment.The projection of deep cerebellar nuclei was situated in V.o.a, V.o.p (posterior part of basal part of VL), V.o.i (VLm), the intralaminar nucleus (CL), and some part of V. im (the rostral part of VPLo). Projections of the interpositus and dentate nuclei were distributed in a more anterior part than those of the fastigial nucleus. A certain topographical arrangement of the projections of these three nuclei was found in V.o.p, V.o.i and V.im. No significant overlap was detected between projections of the pallidum and the deep cerebellar nuclei within the thalamus. 相似文献
10.
R. N. Lemon R. B. Muir G. W. H. Mantel 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》1987,66(3):621-637
Summary Corticomotor (CM) neurones were identified in three conscious macaque monkeys by the presence of post-spike facilitation (PSF) in spike-triggered averages of e.m.g. recorded from intrinsic hand and forearm muscles during performance of a precision grip task. Post-spike effects were compared with those produced by single-pulse intracortical microstimulation (ICMS), with strengths of 4–20 A, delivered at the site of 47 CM cells. Most muscles facilitated by a CM cell were also facilitated by ICMS at the site of the cell. ICMS effects were stronger: at 10 A, the amplitude of ICMS-evoked facilitation was on average 2.8 times greater than PSF, and 6.9 times greater at 20 A. Onset latency of ICMS-evoked facilitation was consistently longer (by 1.7 and 1.3 ms at 10 and 20 A respectively) than PSF, and it is suggested that this results from the indirect, trans-synaptic excitation of CM cells by ICMS. Post-spike suppression was rarely seen (7/421 compared to 105/421 cases of PSF). In contrast, suppression and facilitation were equally common in response to ICMS. The synaptic mechanisms underlying these effects were explored in 5 anaesthetised macaque monkeys. ICMS facilitated a greater proportion of the tested muscles than did the CM cell recorded at the stimulus site. The results suggest the juxtaposition in the motor cortex of CM neurones with different muscle fields. The merits of STA and ICMS for exploring cortical organisation are discussed. 相似文献